Multi-stage filter system



Nov. 24, 1964 w. M. suPlNGER 3,158,571

MULTI-STAGE FLTER SYSTEM Original Filed Aug. 18, 1958 4 Sheets-Sheet 1 ATTORNEY Nov. 24, 1964 w. M. suPlNGER 3,158,571

MULTI-STAGE FILTER SYSTEM Original Filed Aug. 18, 1958 4 Sheets-Sheet 2 INVENTOR W.M.SUP|NGER ATTORNEY Nov. 24, 1964 w. M. SUPINGER 3,158,571

MULTI-STAGE FILTER SYSTEM Original Filed Aug. 18. 1958 4 Sheets-Sheet 3 INVENTOR. W.M.SUPINGER f ATTORNEY Nov. 24, 1964 w. M. suPlNGER MULTI-STAGE FILTER SYSTEM Original Filed Aug. 18, 1958 4 Sheets-Sheet 4 \NNN N NNN I, N N N NNNNNNNNNN NNN NNNNNNN NNNNNNNN NN NN N N N N v REL \j Wx Hum. uw t m l l I llnvillllllll Ililltillllilllllil NNNNNNNNNNNNNNN NNNN N NNNNNNN NNNNNN NNN NN NNN NN INVENTOR W.M.SUPINGER ATTORNEY United States Patent O 3,15%,571 ll/iilTLSTAGE FEL'EER SYSEEll/i William h1. Snpinger, 25% Fairmount Ave., San Diego, Salif.

riginal application Aug. 18, 1958, Ser. No. 755,616, new Yatent No. 2,933,225, dated .inne 13, 1%1. Divided and this application Mar. 2S, 1961, Ser. No. 95,3%

2 Claims. (131. 2111-514) This invention relates to a means for iltering fluids Which contain small particles of foreign material such as the lubricating oils used in internal combustion engines as, for example, gas, gasoline and diesel engines.

An object of my invention is to provide a sealed hollow enclosing housing in which upper and lower filters are mounted and suitable connections to conduct liquid containing particles of foreign material from a supply or storage container into the housing in such a manner that all the liquid entering the housing passes substantially radially inward through the lower filter which removes most of the foreign particles therefrom and then passes upward through the upper filter which removes the remaining particles, the top portion of the housing having an outlet through which the filtered liquid is discharged and conveyed to the site of use or back to the container.

Another object is to make the enclosing housing cylindrical and of substantially largerdiameter than both lilters to provide an annular space around the filters down which the unfiltered liquid which is introduced near the top of the housing, may pass to reach the lower filter.

Another object is to mount the upper filter on top of the lower one so that the weight of the upper filter is supported entirely by the lower one.

Another object is to provide within the housing a long pipe which extends up through both filters and serves both as a means for positioning the upper filter centrally within the housing and also as a discharge outlet for the filtered liquid.

Another object is to provide a horizontal support within the housing near the lower end thereof, the lower filter resting on this Support which thus carries the entire weight of both filters.

A further object is to provide a conical portion at the bottom of the housing in which sediment and dregs in the unfiltered liquid may settle and he readily removed at intervals by the detachment of a suitable drain plug provided.

Another object is to provide in association with the aforementioned housing and its enclosed lters suitable conduit connections whereby only a portion of the liquid which has passed through the lower filter passes upward through the upper lter which completes the filtering, the remaining portion of the liquid being conveyed to the site of use as, for example, the bearings of an internal combustion engine.

Other objects will become apparent as the description of the invention proceeds. For a better understanding of the invention, reference is made to the accompanying drawings, in which:

FIG. 1 is a longitudinal section of a filter cartridge embodying the invention and portions of screens therein broken away;

FIG. 2 is a section on line 2 2 of FIG. 1;

FIG. 3 is a top view with portions broken away of the cartridge of FlG. 1;

FIG. 4 is a bottom view with portions broken away of the cartridge of FIG. 1;

FIG. 5 is a view in section and partly diagrammatic of a filter system embodying the invention and;

FIG. 6 is a view partly in section and partly diagrammatic of a modified form of filter system.

This application is a division of my pending application Ser. No. 755,616 filed August 18, 1958, issued as patent No. 2,988,225. Referring first to FGS. l to 4, the invention comprises a thin cylindrical metal casing 10 to whose upper and lower ends are sealed, as Aby crimping or soldering, an upper cover 11 and a lower cover 12 preferably stamped Vfrom sheet metal. At its center each cover has a cylindrical projection 13'within which is'seated a centering and sealing gasket or Washer 14 of cork, leather or like material, these gaskets abutting the ends of a central cylindrical tube 15 which is thus held concentric with casing 16. The gaskets 14 thusseal the joints between the ends of tube 15 and the covers 11-12. Bottom cover 12 haspa set of narrow radially extending depressions 16 pressed therein which provides a plurality of radially extending passages 17 adapted to convey liquid radially outward along the bottom of a filter 18, the liquid to be filtered entering through a set of small holes 19 made through cover 12 preferably near projection 13. However for some installations holes 19 may be imade further out along depressions 16. Upper cover 11 has radially extending projections 21B similar to depressions 16 in cover 12 to provide a set of radial passages Z1 which convey the filtered liquid in toward two or more `holes'ZZ drilled through tube 15 near the top thereof. A circular wire screen 23 surrounds the top of tube 15 and rests against the bottom face of cover 11, the screen near its center seating against the upper end of a `conical shaped metal ring 24 whose lower end contacts the outer face of tube 1S just below the holes Z2. A circular wire screen 25 is seated against the bottom o f filter 13 and the top of cover 12 but this screen is not essential to the operation of the filter and may be omitted, if desired. Filter 13 comprises a body 26 of fibrous material in intimate contact with tube 15 and casing 141, two cylindrical wire screens 27,V k28 concentric with casing 10 being embedded in the fibers many of which extend into the meshes of the screens. Instead of being made of wire, each cylinder may be a strip of thin metal perforated with many holes or the two cylinders may be replaced by a single spiral screen of increasing radius embedded in the fibers. The fibers composing the filter material may be cotton fiber or a mixture of cotton and other bers such as wood, hemp, sisal, cocoanut or other material having fine fibers which can be packed close enough together to remove small particles of vforeign material from the liquid passing up through filter 1S. The particular fibers used depend on the nature of the liquid to be filtered particularly its viscosity and also on the sizes of the particles of foreign material suspended in theliquid. For filtering "thecrankcase oil of internal combustion engines,`l have found cotton waste to be excellent. 4

interposed between the top of lter 15 and screen 23 is a fabric cover 29 of fine mesh which, asshown, has cylindrical edge portions which extend down a suitable distance along tube 15 and casing 1t). l have found that muslin of from 56-56'weave to 804-80 weave (threads per inch) provides a cover which will effectively stop any particles of foreign material which havey passed vup through filter 1S due to any .possible malfunctioning thereof.

In operation the liquid tobe lftered is passed under pressure into the bottom of the cartridge through holes 19, the radial passages 17' 'serving to convey it'outward until it entirely coversthe bottom of filter 18. The meshesy of screen 25 valsoassist the flow of theliquid in the yspace under filterr 18. Screen 25 'also serves, when cover 12 is being attached to the end of casing'lt), to prevent any loose :strands of cotton hanging from the filter from getting between the cover Vand casing and thus possibly preventing a tightseal ibetween these members. The liquid travels slowly up through filter 18, its flow tending Ito move the fibers composing the filter Q up .and pack them together into a dense mass which would increase substantially the resistance to the flow. The presence of screens 27-23 serves to support the fibers in a fixed position and prevents such upward movement and packing together of the fibers. Also the cylindrical passages formed by the meshes of screens 2.7-28 assist the upward flow. Upper screen 23 prevents the fabric cover 29 and fibers at the upper end of filter 18 from -being pushed up into the radial passages 21 and yagainst top cover 11 which would prevent the free passage of liquid inward lalong the top of filter 18 .toward ldischarge cone 24. The filtered liquid issuing through cover 29 passes inward through the clear space provided by the meshes of wire screen 23 and radi-al passages 21 and is discharged into cone 24 which guides it into outlet holes 22 of the cartridge.

The cartridge described has utility in many types of filter systems and two uses for it are disclosed in FIGS. and 6. Referring to FG. 5 a -lter cartridge 3@ of the type above described is lmounted on and supported by a filter assembly 31 of the construction disclosed in my U.S. Patent No. 2,703,650 of March 8, 1955. Filter 31 comprises an outer cylindrical fabric cover 32 and an inner cylindrical fabric sleeve 33 which engages the turns of a long compression spring 34. A circular metal ring 35 is embedded in the top of the filter land a similar Iring 36 in the bottom, cover 32 and sleeve 33 being interlocked with rings 35, 36 by engagement of folded overlapping portions thereof between the opposite ends of spring 34 and said rings -as more fully described in my above patent. The annular space between sleeve S3 and cover 32 is filled with filter material 37 and a body of the same material fills the space between ring 35 and the top portion 39 of cover 32 which presses against Ithe bottom cover 12 of cartridge 30. Cartridge 30 is thus supported by filter 31.

Cant-ridge 3d and filter 31 are enclosed in a sealed housing 4@ whose cylindrical ver-tical 41 is of substantially larger diameter than that of cartridges 3f) and 31 to provide a clear annular passage 42 for the flow of liquid around the cartridges. Housing has a conical shaped base 43 in which sediment can gradually collect and be withdrawn at intervals by the removal of a threaded drain plug 44. Base 43 has a long opstanding outlet pipe 45 and a surrounding sleeve 46 having an integral projecting ange 47 on which the base of filter 31 rests so that liange 47 supports the weight of filter 31 .and also cartridge 30. The top of housing 4t) has a rounded cover 48 which is hermetically sealed to the top of cylindrical wall 4l. The top of pipe 45 is externally threaded to receive a headed nut 50 the bottom face 49 of which forms va sealed joint with cover 48. As shown, the lower end of nut Sll bears against the top cover 11 of cartridge 30. From the construction described it will be clear that :spring 34 keeps a substantial area of the top portion of lter 31 pressed firmly against the bottom cover 12 of cartridge 3d. Below the level of holes 22 in tube 15, pipe 45 is provided with one or more holes 51 to conduct the filtered liquid into the pipe. It will be noted that sealing washers 14 engage the outer face of pipe 45 to form sealed joints therewith and that these washers together with cover projections 13 serve to position the cartridge sylnetrically with lrespect to pipe 45 and housing 40.

Lubricating oil 52 in the oil pan 53 of the crankcase of an internal combustion engine (not shown) is raised by pump 54 and portion of it conveyed via pipe 5S to the usual oil gallery of the engine which conveys it in a known manner to the engine bearings and other surfaces requiring lubrication. The remainder of the oil is conveyed via pipe 56 and inlet port 57 of housing 40 into annular passage 42. The oil goes down this passage to form an annular pool which entirely surrounds fil-ter 31, flows radially in through the filter material 37, 38 which retains the major portion of any .4 parti-cles of foreign matter suspended in it. lu the case of an automobile engine such particles comprise small carbon particles, metal chips, metal powder and other contaminants. The partly filtered oil next passes up in the space along spring 34, enters the inlet holes 19 of cartridge 3l) and passes up through this cartridge where the filtering is completed in the manner above described. The filtered oil passes through outlet holes 22 and lls up the annular space between pipe 45 and tube 15 until it reaches the level of the hole 51 in pipe 45 when it flows 'down inside this pipe and is returned via a conduit 5S screwed into the bot-tom of pipe 45 to oil pool 52. Alhough conduit 58 is illustrated as being short, it will be under-stood that it may be several feet long and, in all installations is long enough to return the filtered oil to pan 53. From the above it will be clear that a definite portion of the oil circulating in the system is constantly being passed through filters 31 and 3ft in succession to be purged of particles of foreign material. After the oil passing through pipe 55 has lubricated che desired parts, it is returned via la conduit (not shown) tto oil .pool 52 for re-use.

FG. 6 shows a lubrication system generally similar to that of FIG. 5 in which corresponding parts are designated by lilre reference numbers, the construction of housing 4l) and its contained filters 3l), 31 being the same as those described in connection with FIG. 5. n this case however, pipe 55 which conveys the oil to the oi-l gallery is not connected to pipe 56 but to the outlet of a pressure relief valve 59 and also to a pipe 6l) the end 61 of which connects into conical ybase 43. The inlet of relief valve 59 is connected to the lower end of housing 43 by pipe 62.

When starting the engine the pool of oil 52 is cold and the oil is raised by pump 54 and discharged into inlet port 57 of housing 4Q. The cold oil passes down passage 4Z and starts to flow through filter 31 which offers enough resistance to the oil flow to cause the presure to build up enough to open relief valve 59 with the result that while a portion of the oil is passing through filter 31 and up through cartridge 3l) for filtration, the major portion is passing through valve 59 and pipe 55 to the oil gallery and engine (not shown) where it becornes heated and is returned via a conduit (not shown) to pool 521. As the oil in pool 5L. gradually becomes heated, its viscosity decreases also the resistance of filter 3l decreases and more oil passes therethrough with the result that relief valve S9 soon closes. Much of the oil which has passed through filter 31 and been filtered thereby now passes through pipes 6d and SS to the oil gallery for lubricating the engine. The balance passes up through cartridge 3d which completes the filtering and is returned in the manner above described to conduit 5S and oil pool 52. Thus while the engine is heating up, as soon as the viscosity of the oil decreases due to its heating and the hot oil is passing freely through filter 31, relief valve 59 closes and thereafter only oil which has passed radially in through filter 3l and up through cartridge 30 reaches the engine. If filter 31 in time becomes nearly or entirely clogged up with carbon deposit or other foreign matter and the oil pressure in passage 42 increases substantially, relief valve 59 will open and relieve the pressure. Most of the oil will then pass through valve 59 and pipe 5 to the engine, the balance will pass through pipe 6l) and up the annular passage surrounding tube 45 into cartridge Sil where it will be filtered and then returned to pool 52.

While the operations of the'filter systems of FIGS. 5 and 6 have been described in connection with the filtering of engine lubricating oil, it will be understood that they may be used for the filtering of many other liquids containing large or small particles of foreign material which must be removed.

Having described my invention, what I claim as new and useful and desire to secure by Letters Patent is:

1. A multi-stage filter comprising, in combination: a hollow sealed generally cylindrical housing; a sealed cylindrical casing disposed within the upper portion of said housing, said casing having upper and lower covers; inner and outer cylindrical vertical walls connected to said covers, said inner wall being provided near its upper end with a plurality of outlet holes therethrough, said upper cover and outer wall being imperforate and said lower cover having a plurality of angularly spaced apart inlet holes therethrough and communicating with the interior of the casing between the inner and outer cylindrical walls; a body of filter material substantially lling the interior of said casing; a vertical outlet tube extending concentrically up inside said housing and casing with the upper and lower covers being sealed to the outlet tube, said outlet tube near its upper end and between said covers having an opening therethrough adapted to convey filtered liquid which has passed up through said body of filter material and through said outlet holes; a long annular lter mounted in said housing below said casing, said filter having a fabric outer wall spaced from said housing to provide an annular passage therebetween and a fabric cylindrical inner wall concentric with said outlet tube and spaced therefrom to provide therebetween a vertical iiow passage which communicates directly with the inlet holes in said lower cover, said filter having a porous top wall pressing against said lower cover to support the entire weight of said casing and means at the bottom thereof for sealing said annular passage from said vertical flow passage; and means for conveying pressurized liquid to be ltered into said annular passage to substantially fill said passage whereby the liquid passes radially inward through said porous fabric and annular lter and then upward through said vertical flow passage and the inlet holes in said lower cover and said body of iter material.

2. A filter as claimed in claim 1, in which a long coil spring is disposed in said vertical flow passage with a plurality of turns in Contact with said fabric cylindrical inner wall, said spring being arranged to exert upward pressure on the top portion of said annular ilter.

References Cited in the le of this patent UNITED STATES PATENTS 2,522,975 Voorhees Sept. 19, 1950 2,559,267 Winslow et al July 3, 1951 2,601,404 Lasky June 24, 1952 

1. A MULTI-STAGE FILTER COMPRISING, IN COMBINATION: A HOLLOW SEALED GENERALLY CYLINDRICAL HOUSING; A SEALED CYLINDRICAL CASING DISPOSED WITHIN THE UPPER PORTION OF SAID HOUSING, SAID CASING HAVING UPPER AND LOWER COVERS; INNER AND OUTER CYLINDRICAL VERTICAL WALLS CONNECTED TO SAID COVERS, SAID INNER WALL BEING PROVIDED NEAR ITS UPPER END WITH A PLURALITY OF OUTLET HOLES THERETHROUGH, SAID UPPER COVER AND OUTER WALL BEING IMPERFORATE AND SAID LOWER COVER HAVING A PLURALITY OF ANGULARLY SPACED APART INLET HOLES THERETHROUGH AND COMMUNICATING WITH THE INTERIOR OF THE CASING BETWEEN THE INNER AND OUTER CYLINDRICAL WALLS; A BODY OF FILTER MATERIAL SUBSTANTIALLY FILLING THE INTERIOR OF SAID CASING; A VERTICAL OUTLET TUBE EXTENDING CONCENTRICALLY UP INSIDE SAID HOUSING AND CASING WITH THE UPPER AND LOWER COVERS BEING SEALED TO THE OUTLET TUBE, SAID OUTLET TUBE NEAR ITS UPPER END AND BETWEEN SAID COVERS HAVING AN OPENING THERETHROUGH ADAPTED TO CONVEY FILTERED LIQUID WHICH HAS PASSED UP THROUGH SAID BODY OF FILTER MATERIAL AND THROUGH SAID OUTLET HOLES; A LONG ANNULAR FILTER MOUNTED IN SAID HOUSING BELOW SAID CASING, SAID FILTER HAVING A FABRIC OUTER WALL SPACED FROM SAID HOUSING TO PROVIDE AN ANNULAR PASSAGE THEREBETWEEN AND A FABRIC CYLINDRICAL INNER WALL CONCENTRIC WITH SAID OUTLET TUBE AND SPACED THEREFROM TO PROVIDE THEREBETWEEN A VERTICAL FLOW PASSAGE WHICH COMMUNICATES DIRECTLY WITH THE INLET HOLES IN SAID LOWER COVER, SAID FILTER HAVING A POROUS TOP WALL PRESSING AGAINST SAID LOWER COVER TO SUPPORT THE ENTIRE WEIGHT OF SAID CASING AND MEANS AT THE BOTTOM THEREOF FOR SEALING SAID ANNULAR PASSAGE FROM SAID VERTICAL FLOW PASSAGE; AND MEANS FOR CONVEYING PRESSURIZED LIQUID TO BE FILTERED INTO SAID ANNULAR PASSAGE TO SUBSTANTIALLY FILL SAID PASSAGE WHEREBY THE LIQUID PASSES RADIALLY INWARD THROUGH SAID POROUS FABRIC AND ANNULAR FILTER AND THEN UPWARD THROUGH SAID VERTICXAL FLOW PASSAGE AND THE INLET HOLES IN SAID LOWER COVER AND SAID BODY OF FILTER MATERIAL. 